Containment loss of

Hazards from combustion and runaway reactions play a leading role in many chemical process accidents. Knowledge of these reactions is essential for control of process hazards. It is important that loss of containment be avoided. For example ... 

Loss of containment due to mechanical failure or misoperation is a major cause of chemical process accidents. The publication. One Hundred Largest Losses A Thiiiy Year Review of Propeity Damage Losses in the Hydrocarbon Chemical Industry, 9th ed. (M M Protection Consultants, Chicago), cites loss of containment as the leading cause of property loss in the chemical process industries. 

The relative size of hazard zones from possible loss of containment and releases to the atmosphere is much smaller for the cases in which the material is diluted, compared to the anhydrous materials. This is illustrated in Fig. 26-28 for monomethylamine. 

Refrigeration Loss of containment of a liquefied gas under pressure and at atmospheric temperature causes immediate flashing of a large proportion of the gas. This is followed by slower evaporation of the residue. The hazard from a gas under pressure is normally much less in terms of the amount of material stored, but the physical energy released if a confined explosion occurs at high pressure is large. 

The rate of release, in the event of loss of containment, will be reduced because of the lower vapor pressure in the event of a leak. 

Instrumentation (Arthur D. Little, Inc., and Levine, 1986.) Instrument systems are an essential part of the safe design and operation of systems for storing and handling highly toxic hazardous materials. They are key elements of systems to eliminate the threat of conditions that could result in loss of containment. They are also used for early detection of releases so that mitigating ac tion can be taken before these releases result in serious effects on people in the plant or in the public sector, or on the environment. 

Identify the scenario. What can go wrong to result in the loss of containment of the material ... 

Use of materials sensitive to shock, high temperature or high pressure. If the material is inadvertently exposed to an unsuitable condition, or if the process moves out of the safe operating limits, it could result in a loss of containment. 

Primary concerns include the of loss of containment and the potential for exposure of operating personnel to hazardous materials the potential for other hazards such as fires or explosions and the ergonomic issues inherent in manipulating large, heavy containers. The first two concerns are of particular significance in batch operations, since operating personnel are often more frequently and more intimately exposed to the batch processes than is typically the case with continuous processes. 

Cyclic nature of Implement mechanical integrity program batch process (e.g.,, Design equipment for easy replacement start/stop, thermal cycling). Possibil- Consider demand of cycling while designing ity of mechanical equipment and controls wear and tear. Possible loss of containment. ... 

Hot bearing/seals causing ignition of flammables in vapor space. Localized initiation and possible propagation of decomposition or loss of containment. 

Lids and/or inspection ports opened while in operation leading to loss of containment, loss of inerting, operator exposure. 

Temporary connections offer a lot of flexibility to operations but also creates concerns about increased operator exposure, loss of containment, and the ability to add the incorrect material or charge to the incorrect vessel. 

Frequent disas-sembly/assembly of equipment increases mechanical wear resulting in possible loss of containment. 

Nitrogen blow Provide level indicator in feed vessel with through into alarm/interlock drum from feed vessel during pressure transfer leading to loss of containment. AGA XK0775 CCPS G-3 CCPS G-15 CCPS G-22 CCPS G-23 CCPS G-29 FMEC 1997... 

Maintenance or cleaning of equipment Residues Loss of containment (breaking lines) Stripping insulation Burning-off paint, flame heating components Reaction or vaporization of cleaning products... 

Procedures for the rapid assessment of the likely consequences in the event of, e.g., loss of containment of a hazardous material (identify the nature and quantity of material lost, check wind direction, determine from a map probable areas to be affected and the likely population density threatened). 

Prevent loss of containment due to exceeding equipment design strength. 

General emergency (GE) Actual or imminent substantial core degradation loss of containment possible Releases reasonably expected to exceed Federal guidelines Recommendatiort-s to evacuate/shcltcr lor. i 2-mile radiu.s. t.lidler downwind expected to -.L-cior. lo ovo miles... 

Where a cupboard is fitted with a bypass, it should be designed with an air velocity that is sufficiently high to prevent the escape of contaminants. This is particularly important where the cupboard is likely to be subjected to high heat loads, which could cause strong thermal currents in the upper part of the cupboard. However, the velocity should not be high enough to disturb the flow inside the cupboard and cause loss of containment. 

While RP14C provides guidance on the need for process safety devices, it is desirable to perform a complete hazards analysis of tlie facility to identify hazards that are not necessarily detected or contained by process sLifety devices and that could lead to loss of containment of hydrocarbons or otherwise lead to fire, explosion, pollution, or injury to personnel. The industry consensus standard, American Petroleum Institute Recommended Practice 14J, Design and Hazards Analysis for Offshore Facilities (RP14J), provides guidance as to the use of various hazards analysis techniques. 

Proper materials of constrnction for the flame arrester and piping mnst be selected to minimize corrosion, which if nncontrolled, conld possibly resnlt in catastrophic failnre and snbseqnent loss of containment. 

A BLEVE involving a container of flammable liquid will be accompanied by a fireball if the BLEVE is fire-induced. The rapid vaporization and expansion following loss of containment results in a cloud of almost pure vapor and mist. After ignition, this cloud starts to bum at its surface, where mixing with air is possible. In the buoyancy stage, combustion propagates to the center of the cloud causing a massive fireball. 

In the present context, the term BLEVE is used for any sudden loss of containment of a liquid above its normal boiling point at the moment of its failure. It can be accompanied by vessel fragmentation and, if a flammable liquid is involved, fireball, flash fire, or vapor cloud explosion. The vapor cloud explosion and flash fire may arise if container failure is not due to fire impingement. The calculation of effects from these kinds of vapor cloud explosions is treated in Sections 4.3.3 and 5.2. 

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